You need money to run your business, from customers and investors.
Raise as much as you can reasonably get, any time you can get it.
The caveat being don’t raise all that money for a plan or idea you don’t want to do. Raise it for the right idea you want to achieve in the increment of money you raise.
At Virgin Mobile we existed on monthly transfers from Virgin for nearly 3 years. Then raised a ton ($500mm). At Peek we raised $10mm on day 1 which was too much I think, since it was enough to both develop a product platform and launch it, the latter being a bit too much too soon.
And this gives you a philosophy on pricing. Get customers to give you the other part of what you need. If you raise nothing in investment, you will have to get all you can from customers.